A robot having an articulated arm generally includes motors and joints. The motors are located at the axes of the respective joints to actuate the joints. Such a robot is controlled by a controller with the supply of electric power to the motors. Therefore, the controller and the robot are connected via cables. Generally, such cables are bundled up. Also, such cables are usually accommodated inside the robot and connected to respective parts from the inside, in order to save space or avoid the cables per se from becoming a hindrance. Due to the ever-increasing complexity of robotic systems, careful planning with regard to cable positioning and accommodation of joint movement is required as robotic cells are designed.
In particular, cables passing through moving joints must accommodate the various mechanical displacements without excessive mechanical wear due; these displacements may alter the bending load of the cables and/or changes in their diameters due to twisting (or torsion) of the joints. For example, cables passing through robotic joints ideally have a large and uniform bend radius to minimize cable deformation and homogeneously distribute the bending load thereon. The large and uniform bend radius, however, may be difficult to achieve in a space-constrained package of the robotic system (e.g., the joints).
For a conventional structure, as shown in FIG. 1, cables are fixed in a U-shaped and flat form. This cable management system may prevent friction between each of the cables and each of the members that produce rotation. But the working range of its rotary shaft is limited within ±170 degrees.
However, due to the ever-increasing working range, it is required for servo motor and gearbox to rotate over ±170 degrees, even up to ±290 degrees. The known cable harness does not satisfy this need. For example, it is difficult for a joint with cables that transmit signals or power, and for air hoses to rotate over ±170 degrees, even up to ±290 degrees accordingly.
For this reason, there is a need in the art to develop an improved cable-management system.